Alewife, herring could come streaming back with passages
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Shad may be the star when officials talk about restoring migratory fish to the Bay’s tributaries. But the real beneficiaries could someday be smaller fish that few people are familiar with: alewife and blueback herring. Almost indistinguishable from one another, they are collectively referred to as river herring.
Like shad, they spend most of their lives swimming along the coast, but return to their natal rivers and streams to spawn.
Unlike shad, which stay mainly in larger rivers, the river herring will move into smaller headwater streams and ponds to spawn.
Historically, they packed streams in such large numbers that settlers gave them another name: “glut” fish. “In the spring of the year, herrings come up in such abundance into their brooks and fords that it is almost impossible to ride through without treading on them,” wrote early Chesapeake historian Robert Beverly in 1705. Herring were so thick, he wrote, that “even the freshest of rivers … stink of fish.”
In sheer numbers, river herring greatly outnumbered shad. In the 1830s, as many as 750 million herring were taken during an eight-week spawning season on the Potomac River, compared with 22.5 million for shad. And the number of herring were considered to be “not more than one-fourth of the total number in the river during the season,” according to Spencer Baird, of the U.S. Commission of Fish and Fisheries, in an 1886 report.
While shad are rebounding — helped in large part by major hatchery-based stocking efforts in all of the Bay states — river herring abundances remain low. “As much as we’ve been encouraged by statistically significant increased abundances for American shad and hickory shad in the James, the bottom has just dropped out for the blueback herring and the alewife,” said Greg Garman, head of Virginia Commonwealth University’s Center for Environmental Studies.
In fact, a 1991 Bay Program report stated, “Of all the anadromous fish species harvested in the Chesapeake Bay, the river herrings experienced the most drastic decline in commercial landings.”
As recently as 1931, more than 25 million pounds of river herring were harvested in the Bay, making them second in quantity and fifth in value of all Chesapeake finfish.
By the 1990s, the commercial catch was almost nonexistent. In 1996, only 1.4 million pounds were caught along the entire East Coast.
Much of the population collapse was blamed on foreign fishing fleets. During the 1960s and early 1970s — before the United States restricted fishing within 200 miles of its coast — the fleets were often seen harvesting fish within sight of the beach.
In 1969 alone, the foreign fishery is estimated to have taken 74 million pounds of river herring — on top of the U.S. harvest. The heavy fishing pressure took many fish before they had a chance to spawn, sending the population into a downward spiral from which it has yet to recover.
Any comeback is hindered by plenty of other problems: the loss of essential spawning and nursery habitat because of water pollution and the construction of dams and other fish blockages. While little fishing effort is targeted at river herring today, concerns remain that large numbers may be taken as bycatch in other commercial fisheries.
River herring also suffer from neglect. Historically, people have always favored shad, their larger cousin. While early settlers greeted spring herring runs as a fresh source of food — one that often delivered them from starvation — the fish were often harvested for less glamorous purposes, such as fertilizer. Even today, most commercially caught herring are ground up for fish meal or pet food, or used as bait. In contrast, shad remain highly prized for their meat, their eggs or roe, and their fighting ability at the end of a fishing line.
As a result, justifying the large-scale hatchery operations for herring, like those that are rebuilding the shad stock, is difficult. “We have to downplay river herring because we can’t attach those huge recreational fishing benefits to them like we do with shad,” said Richard St. Pierre, Susquehanna River Coordinator for the U.S. Fish and Wildlife Service.
So, while shad are stocked by the millions, the most that has happened for herring in recent years is that biologists trucked a few thousand upstream of dams on the Susquehanna and James rivers in the hope that they will produce young that will “imprint” on those upstream areas and someday return to spawn. Some small upstream dams have also been removed in the hope that herring will someday return.
The stocking effort was stepped up this year when, in the Anacostia River, 2.6 million hatchery-reared herring larvae were released as part of a larger multimillion dollar fish passage and restoration project funded with mitigation money from the construction of the new Woodrow Wilson Bridge over the Potomac. Officials focused on river herring, because, unlike the larger shad, which confine themselves to bigger waterways, river herring will swim into smaller headwater streams.
“We don’t have much of a shad run in the Anacostia,” said John Galli, Anacostia restoration program manager with the Metropolitan Washington Council of Governments. “We know from historic evidence that these fish did go pretty far up into these stream systems at one time, but in the past 100 or more years, they’ve taken it on the chin.
“We may not get big herring runs in the Anacostia for some time to come,” he added, “but we may be able to get the herring running pretty far up into these tributary streams and that will promote greater interest in the watershed, and in the restoration of the watershed, which is really what we are all about.”
But rearing herring in hatcheries is more difficult than it is for shad. So rather than releasing small fish, or “fry,” as is done with shad, the Anacostia operation released much smaller, almost microscopic larvae, which are more vulnerable to predation.
“When I throw the larvae in, I feel like I just fed all of the sunfish and the minnows and everything else hanging around in the area,” said Phong Trieu, an aquatic biologist with the Metropolitan Washington Council of Governments. “Hopefully, if we do this a number of times over many years, we will get some good recruitment.”
In fact, efforts to rebuild river herring stocks may be compounded by the fact that almost everything likes to eat them, from other fish to reptiles, amphibians, mammals — even birds. A study at one Connecticut lake estimated that only one out of every 80,000 spawned alewife eggs produced a juvenile fish that escaped alive. (An adult female can produce between 100,000 and 467,000 eggs.) When millions of river herring packed spawning streams, such predation wasn’t a problem. But a recent Chesapeake Bay report raised concerns that high levels of predation on today’s reduced stock could slow the natural recovery of the stocks.
That problem could be compounded, Garman suggested, by the introduction of nonnative predators, such as the blue catfish, the flathead catfish and others. When there were big spawning runs in the rivers, he said, predators were few. “Now, they’ve got to run this gantlet of large, very efficient predators,” Garman said. “I think we’ve just seen the beginning of a significant new source of mortality.”
A restored herring population would bring a number of other benefits, although they are harder to quantify. More herring would mean more forage for predators in the rivers and the Bay. Research has shown that the large numbers of river herring that once glutted headwater streams were an important source of nutrients in those areas. This provided other ecological benefits as well. One study, for instance, found that the deaths of migrating alewife reduced sedimentation rates in lakes by furnishing nitrogen and phosphorus, which stimulated the growth of organisms that devoured leaf litter.
There is also economic potential for the fish. They are popular, especially in New England, both pickled and salted. As recently as the early 1960s, dip netting for herring during spawning runs was so popular at some locations on the banks of the upper Chesapeake Bay and lower Susquehanna River that it was sometimes difficult to find a space to dip on March and April nights during spawning runs.
While river herring are not targeted for restoration as aggressively as shad, efforts that help shad — such as cleaning the water, building fish passages and removing tributary dams — will also help alewife and blueback herring. In fact, biologists expect river herring to someday dwarf shad abundance in the Susquehanna basin, where targets are set. Above the southernmost Conowingo Dam, the goal is to eventually get 3 million shad — but 20 million river herring.
But, St. Pierre, of the U.S. Fish and Wildlife Service, acknowledges the river herring goal is “really a shot in the dark.” No one actually knows how many herring swam in the river in past centuries. Typically, though, smaller herring outnumber larger shad in coastal rivers, sometimes by as much as 10-to-1, St. Pierre said.
Big numbers remain a long way off. But, blueback herring and alewife have occasionally shown promising signs in various Bay tributaries. As many as 300,000 bluebacks have been seen at Conowingo Dam in recent years, although other years have seen only a few hundred.
That offers a glimmer of hope that, with the right mix of environmental conditions, and a bit of help, that number could eventually mushroom. “At some point, it could suddenly turn into several millions,” St. Pierre said.
River herring come in two varieties, alewife and blueback herring. The two fish are almost identical in appearance and both are usually referred to simply as river herring. Alewife range along the Atlantic Coast from Newfoundland to South Carolina, with their population center off New England. Blueback herring range from Nova Scotia to northern Florida, with their population center off the southern states. Although both were historically abundant in the Mid-Atlantic. Both can grow to lengths of nearly 15 inches, the blueback is slightly more elongated, and has smaller eyes than the alewife.
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